Abstract : The patent describes an automatic threshold detector which provides a variable-threshold correction voltage that allows a selectively predetermined percentage of an incoming signal to exceed a threshold voltage when the signal is sampled at a given rate. The detector generates a logic 'one' for each crossing and a 'zero' for each non-crossing of the threshold. The 'one' and 'zero' counts are then converted by digital techniques into a feedback correction voltage to maintain the selectively predetermined percentage of 'ones' at the output.